1. Field of the Invention
This invention relates to a vehicle lighting and signaling device and an improved lens having at least one coupler for improving light distribution.
2. Description of the Related Art
In the field of motor vehicle lighting and signaling, it is increasingly commonplace to have headlamps with lenses that have curved or arcuate surfaces. One problem that designers face is the visibility regulations imposed by the regulating authorities. Sometimes it is difficult to incorporate these visibility regulations in modern lamp designs because of the outer lens rake and sweep angles as well as the functions being placed far back in the headlamp assemblies themselves. The regulatory authorities require very particular visibility angles that are difficult to achieve with the new headlamp designs. For example, some countries require a light pattern visibility of approximately 45 degrees (inboard) to 80 degrees (outboard).
It has been found that providing visibility light in a lateral and sometimes vertical direction, of the main optical axis of the headlamp, is difficult to achieve. In some prior art embodiments, the headlamp assembly included additional light sources or optics that improve the lateral and vertical visibility light. To illustrate this, FIG. 1A is a cross-sectional view of an outer lens having no modification, indicated by the arrows labeled NM. Note that the light ray, which may be a ray from a light source within the headlamp assembly, reflects off an inner surface of the lens due to the angle of incidence exceeding the critical angle according to Snell's Law. This results in decreased illumination, particularly toward the edges or corner areas of the lens.
FIG. 1B illustrates one prior art solution that includes inner lens optics and a separate light source LS that would illuminate near the edges and cooperate with the inner lens optics to provide increased lateral illumination.
FIG. 1C illustrates that some current solutions include outer lens visibility optics, such as gnoracles GN. German Patent DE 102010027415A1 shows a solution using a lens having a gnoracle.
Unfortunately, these solutions were sometimes not pleasing to designers or customers due to the uneven or, perhaps, even unlit appearance of the headlamp in the curved or edged regions of the headlamp. Space and styling of the headlamp assembly also would usually not allow for an additional lamp to improve visibility and light distribution. The additional lamp also added increased cost to the headlamp assembly and also provided unique design challenges.
What is needed, therefore, is a vehicle lighting and signaling device that overcomes one or more of the aforementioned problems.